In a tunnel under the streets of downtown Baltimore, a train transporting dangerous chemicals derailed. Manhole covers exploded, city businesses shut down for a week and firefighters risked their lives battling the 1,500 degree fire.

Heinbuck was in charge of the response 10 years ago. Although nobody was seriously hurt, analysis found a need for better teamwork and communication.

That’s why training drills are now held every year.

“I think we could [handle any emergency],” Heinbuck said.

But some critics say only focusing on response training ignores the real danger.

“We need some major changes, like we need a new tunnel,” said former Congresswoman Helen Bentley.

Bentley is a well-respected expert on transportation issues. Since the 1970s, she’s been pushing for a $1 billion replacement.

“All of the north/south traffic on the East Coast goes through that tunnel,” Bentley said. “And if there’s ever a real breakdown, an explosion or terrorist, we’ll have real trouble in this country. We need to do something about it.”

“I think we would love to have a new tunnel, but not for safety reasons,” said Mayor Stephanie Rawlings-Blake.

Rawlings-Blake toured the tunnel last fall. It’s a mile and a half long under busy areas such as Lexington Market and First Mariner Arena, ending at Camden Yards. At more than 100 years old, it’s a single lane with low clearance, too small for modern, bigger trains.

“If we were to have a deeper tunnel with double-stacked trains, we could expand job opportunities in and around the port,” Rawlings-Blake said.

A spokesman for train company CSX also says calls for a new tunnel are a commerce issue, not a safety issue.

“The tunnel structure is old but we believe it is a very safe way to move,” said Bob Sullivan.

Last August, another train carrying hazardous materials derailed in the tunnel. Luckily, it didn’t catch fire. If it had turned into a repeat of 2001, Bentley feels others would see it her way.

“Redoing that tunnel is a matter of national security,” Bentley said. “They have to come up with the money and they will. Maybe not in my lifetime, but they will.”

On average, more than two dozen trains use the Howard Street tunnel every day.